[QUOTE=leo9;961221
Heat, like spikes, is great if you use it in safe ways. My favourite, which I haven't seen described elsewhere, is to spreadeagle a sub and then put a nice fresh hot water bottle under her ass. No fluffy cover, just scalding hot rubber. You can either leave her straining up off it as a predicament, or have a fuck enlivened by lots of bucking and screams.
[/QUOTE]

Though they do, in fact, burn the skin..